This project tests the outcome of a novel training method for strengthening the muscles of the respiratory system. Targeting the expiratory muscles, the technique is referred to as expiratory muscle strength training (EMST). EMST provides the user with an experimental high-pressure threshold device which places a high physiological load on the muscles during breathing. The treatment lasts 4 weeks and the majority of the training takes place in the person's home. We intend to test the outcome of EMST in a group of individuals with idiopathic Parkinson disease (IPD). Parkinson's disease is a debilitating disease with well-recognized adverse effects on motor function including breathing, cough, swallow and speech. The general purpose of this research is to first determine if those with a specific severity of IPD can improve expiratory muscle strength and secondly to determine what outcome variables are affected by the improvements in expiratory muscle strength. We anticipate improvements in breathing, cough, swallow and speech following treatment that are attributable to the training technique. Study of three groups of 30 subjects with Hoehn & Yahr, stage I-III IPD in a treatment, sham and control group will define the therapeutic effect of this technique. Quantitative measures include measures of volume, flow, sound pressure level and videoflourographic indices as well as listener perception tests to determine the technique's impact on overall sound quality and speech intelligibility. Results from this project will provide new information about the EMST program as a novel technique. The goals of the grant meet the mission of the R21. Its potential impact is high due to the therapy program's innovative nature and potential cost-effectiveness as a treatment approach.